Chinese mining engineers have succeeded in extinguishing a series of subterranean and surface coal fires that had burned for 60 years in the northwest Xinjiang Uygur Autonomous Region.

A report by the Xinjiang regional coal mining, land resources and environmental protection departments published Thursday said the fires had spread over 900,000 square meters at the Tielieke Coal Mine Field.

Cai Zhongyong, chief engineer with the Xinjiang regional coal fire engineering bureau, said the fires caused by illegal mining and spontaneous combustion had been consuming 1.88 million tonnes of coal a year for decades.

Tielieke, boasting deposits of 142 million tonnes of high-quality coal, in Baicheng County, 1,000 km southwest of the regional capital, Urumqi.

Xinjiang's land resources department suspended all mining near the sites in 2004 and began to extinguish the fires. The central and regional government spent up to 89 million yuan on the project.

Cai said the bureau had developed a comprehensive fire-fighting plan that included seam exfoliation, drilling, water injection and earth filling.

"Grass has grown over 1.1 million square meters that had been left barren by the heat of the fires," he said.

Cai said the smoldering fires used to produce huge amounts of poisonous gases such as carbon monoxide and sulfur dioxide.

He said the local authorities had planned to use the same fire-fighting methods to extinguish all other fires in Xinjiang coal fields by 2015.

Xinjiang has 2.2 trillion tonnes of projected coal reserves, accounting for 40 percent of China's total, according to the bureau. However, coal fires caused by oxidizing and mining lead to losses of more than 10 million tonnes of coal a year.

(Xinhua News Agency July 2, 2009)